New research shows that exercise video games such as Wii Sports and Dance Dance Revolution boost children's activity levels significantly.

The Wii system, made by Nintendo, is controlled by a wireless remote that translates movements to its "Mii" caricature on screen. In Dance Dance Revolution, from video game maker Konami, players use their feet to hit arrows on the game's dance mat, matching their own steps with arrows set in time to music on screen.

One study, from the University of Nebraska, measured the heart rate and oxygen consumption of kids playing Wii Boxing, Wii Tennis, DDR and a sedentary auto racing game for 15 minutes each. Another study, based in the Netherlands, monitored the oxygen consumption of children playing six popular exergames, including DDR and Wii Tennis, for five minutes each.

Both studies, presented to members of the American College of Sports Medicine, found engaging in exergames had positive effects.

The Nebraska research showed active video gaming requires more than twice as much energy as traditional video gaming. In the Netherlands study, several of these games raised children's activity levels enough to meet health guidelines for a moderate-intensity activity.

Some schools are adding video games to their programs. West Virginia plans to place Dance Dance Revolution in all public schools by the end of the 2008-2009 school year.

North Carolina is introducing the HOPSports Training System into schools through a partnership with Be Active North Carolina, a non-profit group. The system simulates sports skills, such as bouncing a basketball, and includes cardiovascular and muscle-training equipment.

Still, some experts say exergames won't bring the same results as good old-fashioned exercise.

Craig Buschner, a professor of kinesiology at California State University-Chico, says video games should be seen as a tool, but not the only tool, to help kids become more physically active. Children should not use these games in place of an hour of tag or a bike ride in the park, he says.

He also warns educators and parents not to lose sight of the learning that comes through personal interaction, and not to "become so enamored with technology that you forget about the other kind of learning that takes place in the classroom without technology."